Comparative studies on jet breakup morphologies of non-circular nozzles by using high-speed photography technique

摘要

Based on the principle of equal flow rate with the same pressure, two non-circular nozzles including square and triangular orifice shapes were designed, their hydraulic characteristics were measured and were compared with the circular nozzle. Also, ahigh-speed photography (HSP) technique was used to investigate the breakup process and flow behavior of low-intermediate pressure water jets issued from two non-circular nozzles. It is found that the jet began to break and the jet breakup length increased with the increase of pressure. The jet breakup length of triangular nozzle was the shortest while the jet breakup length of circular nozzle was the longest. With the increase of nozzle cone angle, the jet breakup length of the non-circle nozzles decreased. From the different viewing angles, the breakup of jets was more intense when the jets issued from the surfaces of orifices, while the surface fluctuation ofjets was smooth when the jets issued from the included angles of orifices.